I've been playing around with this concept for a while, I quite like how you've added your own twist here. Perhaps the monsters are referred here by monster rescue agencies? Under many cities, there are disused and closed loops for underground subways, perhaps missing from various maps? It would be one way for those of the supernatural persuasion to make their way about the city - perhaps to other locations, say markets, schools, or even a clinic? I remember reading a book about people digging tunnels and setting up bars and the like.

[quote=@LupusIntus]
I love a spice-of-life story with a little extra spice!

Could I play a normal unsuspecting human who stumbles into this situation and is just terrified of everything/everyone? XD
[/quote]

Perhaps you inherit the place? Or there's a bit of confusion and the tenants believe you're a monster just like them?